Appeared in DIVER March 2008

John John Bantin has been a full-time professional diving writer and underwater photographer since 1990. He makes around 300 dives each year testing diving equipment.


NICKEL-CADMIUM BATTERIES are being phased out. Yes, you read that right. It seems that the bureaucrats in Brussels think cadmium is too harmful a chemical, so wave goodbye to good old ni-cad.
Thats left Mr Kowalski in the lurch. A very particular German, he took the stance that nickel-metal hydride batteries were unsuitable for his diving lamps because they were not up to powering such high-quality equipment.
The British importer has asked me not to say that his manufacturer thought they were crap!
Mr Kowalski nearly got hoisted on his own petard, however, by that directive from Brussels, so now we have the Kowalski 620 Maxum powered by a lithium-iron battery pack instead.
It still has all those desirable features that have made these lamps virtually diver-proof, and it weighs a lot less than some of its siblings.
It also has the usual Kowalski-supplied neoprene sleeve that makes it very light indeed once under water. Nearly everything is right about this lamp, except the price.

Light Source
With a 6V, 20W halogen lamp fitted, the 620 Maxum may seem rather ordinary. No HID, no LED, just a straightforward quartz-tungsten bulb that gives a regular-colour white light and can be switched on and off willy-nilly. The reflector is well designed to make sure that all the light is projected in a strongly focused beam.

Power Source
The li-iron battery can be charged at any state of play. Typically for Kowalski, you dont have to break into the lamp to connect the intelligent charger, which should suit less fastidious divers. You just connect its leads to two outer contacts.
The lamp comes with a warning note that, under current airline safety rules, you must separate battery-pack from lamp when travelling by air. Using a small hexagonal wrench, you slide the aluminium sleeve off the lamp. All the dangers of getting dirt on the sealing O-rings are then reinstated, with the consequent potential for flooding.
I packed my test lamp in my bag, checked it in and said nothing. Had I needed to deal with inspection by the rottweilers of the American TSA, I might have got caught out.
Other than that, the manufacturer has the confidence to give this lamp a 200m depth rating, almost good enough even for Mark Ellyatt. An indicator lamp changes from red through to green to indicate the batterys state of charge, but the burntime at full power is only just long enough for most leisure dives.

A wheel that rotates at the back of the lamp operates it. This can be locked to avoid accidental switching. The first position gives full power, but continue to rotate the wheel and the dimmer reduces the output accordingly.
A reduced output results in an extended burntime. Run it at the lowest setting and youll get it to run for more than 3.5 hours.
The indicator light that glowed during charging now shows green through to red to indicate how much juice is left in the battery.
Should you miss this, the lamp bulb also flashes three times. You can then extend the remaining burntime by turning down the brightness on the dimmer switch.

The beam is a tightly focused yet evenly delivered spot of the type we now expect from Kowalski. It also has a wide peripheral halo to give warning of obstructions, or animals just outside the main area of illumination.
Being conventional tungsten by nature, the light is not fantastically bright compared to that from its bigger HID brothers, but it is of a colour temperature that we humans find comfortable, and its easy to live with.
We did an extended night dive on the Umbria near Port Sudan, and I had the Maxum on a lower brightness setting to extend burntime.
At minimum output it was little better than a glow-worm but, strategically placed, it served as a useful marker to show the short route out during a penetration of the galley area.
Of course, I was using another lamp as my primary at the time. As an experiment, I continued to use the lamp later on during the dive at that low setting as an alternative primary. I was amazed to find that my eyes soon became accustomed to its low output. It seems a little light is a lot better than no light at all.
Tom Briggs (left), a fellow-passenger on Royal Evolution, took it for a whirl one night on the reef at Sanganeb. On his return he told me that it was a very effective unit. It had outlasted his dive and gave plenty of light on full power.
When pushed to be a bit more colourful with his opinion, he retorted: What do you expect me to say Im an accountant!

Salvo HID Handheld £285
Dive Rite LED Torch £335
Metalsub Handlamp XL7.2 (Tungsten) 239

Divernet Divernet
PRICE £306
BURNTIME 65min at full power
EXTRAS Neoprene sleeve and intelligent charger included
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